1. Field
Embodiments described generally relate to systems and methods for improving flow of slurry from a storage vessel that can have a variable concentration of solid particles.
2. Description of the Related Art
In fluid catalytic cracking (FCC) systems, a particulate solid catalyst and liquid hydrocarbon feedstock enter a reactor under specific reaction conditions. The effluent produced by the reaction can then be processed in a series of separators that separate most of the catalyst from the effluent. The separated catalyst can be recycled to a regenerator and then back to the reactor while the catalyst-lean effluent can be cooled and separated into the product constituents.
Residual catalyst entrained in the effluent can be collected with heavier hydrocarbons to form slurry oil. This slurry oil can be recycled to the catalyst regenerator where the hydrocarbons in the effluent can be burned to supply heat to the catalyst regeneration process. In certain FCC processes, there can be a relatively high ratio of catalyst to hydrocarbons in the slurry oil. High concentrations of catalyst in the slurry oil can be problematic if the solid catalyst particles settle out of the slurry oil and interfere with the supply of hydrocarbons to the regenerator.
There is a need, therefore, for improved systems and methods for storing and handling slurries so that solids remain suspended in the slurry oil.